Loop driven vehicles

Abstract

A loop driven vehicle such as a motor cycle has a pivoted fork which supports the rear wheel mounted on the engine unit, and the engine unit mounted at its rear on the frame of the vehicle by a mounting which permits angular movement of the engine unit about a second axis parallel to the axis of rotation of the rear wheel, and fore and aft movement of the second axis. This movement of the engine unit is accommodated by one or more second mountings which permit the fore and aft and angular movement and may constrain the engine unit against movement in other directions. The mounting at the rear of the engine unit may comprise a pivoted member, or a flexible plate secured between the engine unit and frame.

I claim: 
     
       1. A loop driven vehicle comprising a frame, a power unit which produces out of balance forces when in operation, mounting means movably mounting the power unit on the frame, a fork pivotally mounted on the power unit and a rear wheel mounted in the fork for rotation about a first axis, and a driving loop interconnecting the rear wheel and power unit, the mounting means comprising: i. first mounting means at the rear of the power unit for permitting angular movement of the power unit in response to said out of balance forces about a second axis parallel to the first axis and for permitting translatory movement of the power unit relative to the frame, such permitted movement having a horizontal component in a plane perpendicular to said first axis at least a number of times greater than vertical and lateral components of such movement, said first mounting means comprising: a. a generally U-shaped support member with a base portion and two parallel limbs;   b. means for pivotally mounting the limbs to the power unit to define said second axis; and   c. means for pivotally mounting the support member to the frame to define a pivotal axis which is fixed relative to the frame and is parallel to and substantially in vertical alignment with said second axis, and     ii. resilient second mounting means for accommodating movement of a further part of the power unit resulting from said movement of the power unit permitted by the first mounting means.   
     
     
       2. A loop driven vehicle according to claim 1 wherein i. a lug is provided at the rear of the power unit;   ii. a shaft extends through said lug and said limbs adjacent the free ends thereof to constitute said means pivotally mounting the support member to the power unit; and   iii. a further shaft extends through the base portion of the support member and through a frame portion of the vehicle to constitute said means for pivotally mounting the support member to the frame.   
     
     
       3. A loop driven vehicle according to claim 2 wherein said first shaft also constitutes a pivotal mounting for the fork in which the rear wheel of the vehicle is mounted. 
     
     
       4. A loop driven vehicle comprising a frame, a power unit, which produces out of balance forces when in operation, mounting means movably mounting the power unit on the frame, a fork pivotally mounted on the power unit and a rear wheel mounted in the fork for rotation about a first axis, and a driving loop interconnecting the rear wheel and power unit, the mounting means comprising: i. first mounting means at the rear of the power unit for permitting angular movement of the power unit in response to said out of balance forces about a second axis parallel to the first axis and for permitting translatory movement of the power unit relative to the frame, such permitted movement having a horizontal component in a plane perpendicular to said first axis at least a number of times greater than vertical and lateral components of such movement, said first mounting means comprising: a. a resilient plate member having first and second opposite parallel edge regions;   b. means rigidly securing the first edge region of the plate member to the power unit, along a region parallel to said first axis; and   c. means rigidly securing the second edge region of the plate member to the frame along a region parallel to and substantially in vertical alignment with said first region; and     ii. resilient second mounting means for accommodating movement of a further part of the power unit resulting from said movement of the power unit permitted by the first mounting means.